docs: def get_pos_hint_y(poshints, sizehinty):
      """Return ``poshints['y']`` if available, or its computed equivalent
      otherwise.
  
      """
      if 'y' in poshints:
          return poshints['y']
      elif sizehinty is not None:
          if 'center_y' in poshints:
              return (
                  poshints['center_y'] -
                  sizehinty / 2
              )
          elif 'top' in poshints:
              return (
                  poshints['top'] -
                  sizehinty
              )